The present invention relates to a process for optimizing a process flow, and more particularly to optimizing a process flow in a facility having storage facilities (stores) for various raw materials which are supplied to the stores and are processed sequentially.
Nothing in the following discussion of the state of the art is to be construed as an admission of prior art.
Production in industrial processes in general and in the oil industry in particular, is realized in several sequentially arranged planes. Each of these stages includes the actual production step and storage of the produced quantities in specifically provided storage facilities, subsequently referred to as stores or tanks, which are then available for the next production step. The following scenario applies to the production system of a refinery for crude oil:
Crude oils of different composition are purchased in minimum quantities (batches), for example in a petroleum port, are delivered, transported to the refinery, for example, pumped through pipelines, stored on the refinery premises, and then distilled into final products (kerosene, gasoline, oil, gas), which are again stored. Storage tanks are provided exclusively for specific grades of crude oils and/or end products.
The selection of the sequential order (sequence) of the processing of the batches results in different utilization rates of the storage tanks and distillation facilities. Certain hypothetical sequences can also cause infeasibilities, such as time periods when the stores are overfilled and underfilled, or the pumping power is exceeded.
It is therefore an objective to determine a sequence for the processing of batches which minimizes or eliminates these infeasibilities.
Calculating the possible permutations of N, for example 15, batches would require N!, for this example 15! or approximately 1012 computations, making computation within an acceptable time no longer possible.
It would therefore be desirable and advantageous to provide a process which obviates prior art shortcomings and which allows optimization of resources (stores, crude oils, facilities) for refining desired end products, and is able to specifically prevent infeasibilities and optimize sequences with the least computational effort.